Method for conditioning tobacco



Oct. 10, 1967 v LEDERMAN ET AL R 3,345,992

METHOD FOR CONDITIONING TOBACCO Filed Aug. 4, 1965 3 Sheets-Sheet 1 v q,I a 1 III Q Q Q L O /4 //vv/v 705s ARTHUR N LEDERMA/V FRED H L lNDS TROMOct. 10, 1967 A. N. LEDERMAN ET AL METHOD FOR CONDITIONING TOBACCO y w 52 m mmo @M VEW S WW5 v w m m H 3 W0 m9 rs WM RR AF 4 w w A m mhlmw k d hh Oct 10, 1967 A. N. LEDERMAN ET AL I METHOD FOR CONDITIONING TOBACCO 3Sheets-Sheet 3 Filed Aug. 4, 1965 S Q. MQR QN .Q Q\ h ROM mu UnitedStates Patent 3,345,992 METHQD FOR CONDITIONING TOBACCO Arthur N.Lederman, Flossmoor, and Fred H. Lindstrom,

Olympia Fields, 111., assignors to Vacudyne Corporation, Chicago, Ill.,a corporation of Illinois Filed Aug. 4, 1965, Ser. No. 477,252 Claims.(Cl. 131-140) This invention relates to an improved method forconditioning and adjusting the moisture content of bulk products such astobacco which have been stored or confined in hogsheads, bales, boxes,or in similar confining units. More particularly the invention isdirected to an improved process for humidifying or moisturizingmaterials under controlled and direction-oriented cycling conditions ofvacuum and steaming. In a preferred embodiment, the invention findsutility in the conditioning and moistening of domestic and foreign typesof green, semi-dried or re-dried tobacco to prepare the tobacco forfurther processing. Also included within the scope of the invention isthe, apparatus for carrying out the process steps of the invention.

Many different types of processes for the conditioning and moisturizingof tobacco are known in the prior art. However, in each of theseprocesses one or more objectionable features limits or impairs thegeneral usefulness. In some instances the methods employed in thetreatment cause excessive powden'ng or flaking and incident high ratiosof scrap product to useful product. Other techniques require excessiveprocessing times, tying up equipment and increasing over-all handlingcosts. Vacuum techniques of various types have been used. In still othercases pressurized systems have been employed. In some procedures thetightly packed or compressed leaf material has been subjected to contactwith steam, Water or moist air at the exterior bounding surfaces. Invaried techniques, pipes or probes have been driven into the tobacco andWater, steam or moist air introduced into the interior of the mass. Ineach of these and in the other prior art techniques the persistence ofcold spots due to irregular vapor-penetration, failure to remove air orother non-condensible gases, and to the propensity to channeling haveimpaired the general effectiveness of the processes. Uneven andincomplete moisturizing have been the inevitable result.

It is the aim of the present invention to provide a process whichobviates the objectionable features of prior art methods and techniques.

It is a principal object of the invention to provide an improved processfor moistening materials under cycling conditions of vacuum and steamingand utilizing the principles of reverse flow, and duo-directional flow.

Another object of the invention is to provide an improved treatmentcycle for conditioning tobacco and related products whereby excessivewaste is eliminated and a uniformly treated product is obtained.

Still another object of the invention is to provide an improved cyclingprocess in which novel flow reversals through the material being treatedpromote gentle physical agitation of the bulk product and pulsing withinthe mass to provide a plurality of varied and random steam paths throughthe treated material.

A related object of the invention is to provide a tobacco treatingprocess whereby the leaf product is flutfed and loosened during thephysical introduction of controlled moisture.

Yet another object of the invention is to reduce the time required foreffective conditioning of the tobacco.

Other and further objects and advantages of the invention will becomeapparent from a reading of the following specification taken inconjunction with the drawing in which:

FIGURE 1 is an over-all schematic representation of a preferred form ofthe apparatus used in carrying out the method of the invention;

FIGURE 2 is a fragmentary front elevational view of the probe driveassembly of the invention;

FIGURE 3 is a side View of the probe assembly;

FIGURE 4 is a cross-sectional view taken on the lines 44 of FIGURE 2;

FIGURE 5 is a graphic diagram of flow cycles embodying the teachings ofthe present invention; and

FIGURE 6 is a fragmentary cross-sectional view showing a structure forsealing the probe port.

Referring more particularly to the drawings, and especially to FIGURESl, 2, 3 and 4 there is shown, for the purpose of illustrativedisclosure, a preferred embodiment of the apparatus used in carrying outthe invention. In the preferred arrangement depicted, the equipmentillustrated comprises a treating or conditioning chamber 11, which ispreferably an all steel rectangular or cylindrical shaped vacuum vessel,provided with a suitable sealing door 12. In the particular exampleillustrated, the chamber is a 2-hogshead unit, the hogshead 13 beingloaded into the chamber 11 on wheeled platform trucks 14 riding on atrackway 16 extending into the conditioning chamber 11. Verticallypositionable probes 18 extend through packing glands 20 connectedthrough the top wall 21 of the chamber 11. Probe drive units 30 (FIGURES2, 3, and 4) are used to insert or force the probes 18 into the tobacco35 packed in the hogsheads 13. The probes 18 themselves are providedwith sharply tapered ends or points 37 to facilitate insertion into thetightly packed contents of the hogsheads. Longitudinal bores 38 extendaxially throughout substantially the full length of the probes andtransverse radial bores 40 communicate with the longitudinal bores 38 toprovide steam flow paths and evacuation channels or ducts.

The ends 42 of the probes 18 extending or protruding outwardly orexternally of the chamber 11 are coupled to high-vacuum type flexiblehoses 44 connected to a conduit or line 45 adapted to serve as both asteam supply lead and a vacuum lead during the reversing fiow cyclingprocess. A steam supply source (not shown) is connected to the probeunits 18 through a lead line 46, a leg 47, a control valve 49, ashut-off valve 52, and line 45 to the flexible hose 44 through apipe-to-hose coupling 53 and a hose-to-pipe fitting 54. The steam supplyline 46 is branched to provide a leg 56 leading into the conditioningchamber through a conventional shut-off valve 57 and a control valve 58.An auxiliary pipe line 31 downstream of the shut-off valve 52 leads toanother jet suction stage, through a shut-ofi. valve 33 providing meansfor more effective evacuation of air and other non-condensible gasesthrough the probe system.

In the particular arrangement illustrated the over-all evacuation systemincludes a tank or condenser 59, a first stage ejector 60 connectedbetween the conditioning chamber 11 and the condenser 59, and betweenthe probes 18 and the condenser 59, and a second stage ejector 62connected to both the probes 18 and the chamber 11, through thecondenser 59 through an isolation valve 64. The condenser 59 is providedwith a cooling water supply line represented as a water pipe 67extending into the condenser and delivering Water serving as steamcondensation means. A conventional shut-off valve 69 controls the flowof cooling water into the condensation tank 59. The condenser ispreferably of a barometric type and is provided with suitable baffles,piping, etc. (not shown) and a barometric leg or vertical pipe 70connected adjacent its lower end to a water pump 71. The pump 71 may beof a standard centrifugal type to remove Water from the condenser and toensure adequate Water flow velocity. The eifiuent of the water pump maybe discharged to waste or may be directed to a cooling tower (not shown)for ultimate recirculation.

As illustrated schematically in FIGURE 1, the first stage ejector 60 ofthe evacuation system is connected for evacuation of the conditioningchamber 11 through a suitable pipe or duct connection '73 and forevacuation of the probe lines through pipe 31. A line 74 leading from asteam source (not shown), and provided with a shutoff valve 76, inaccordance With accepted and conventional practices, discharges motivesteam into the first stage ejector 60 to provide the aspirating orpumping effect in a manner well-known in the art.

A steam supply source (not shown) is connected to feed motive steam intothe second stage ejector 62 through a lead 84 and a suitable controlvalve 86.

It is apparent from the above detailed description of the structureillustrated that both the chamber 11 and the probes 18 are provided withsteam supplies as well as with vacuum connections. The purpose of thisarrangement will be apparent from a consideration of the followingdescription of the preferred processing methods and the cyclingoperations of the invention. However, before considering the methods ofthe invention, the mechanism by which the probes 18 are lowered andretracted will be described.

It has previously been pointed out that the probes 18 are verticallypositionable to move through glands 20 in the chamber wall from anelevated position in which the probes are above the tobacco contained inthe hogshead 13 to a lowered, functional position in which the probes 18extend into the tobacco for evacuation and for steam introduction.Referring now to FIGURES 2, 3 and 4, there is shown, for purposes ofillustrative disclosure, a preferred structure for a probe drive unit 30by which the probes 18 are selectively positioned. Mounted above theevacuation and steaming chamber 11 is a yoke 90 which is shapedgenerally in the form of an inverted U constructed of channel irons todefine a pair of vertically extending, facing, and inwardly openingchannels or guideways 92 and 9 3 surmounted by a bridging channel memberor bar 95. The lower ends of the vertically extending channels or guides92 and 93 are connected to a base plate 97 which is in turn fastened toa mounting plate 99 welded to the top wall 21 of the chamber 11.

A gear motor 101 is supported from one of the lateral channels 92 bymeans of a bracket 103, and a sprocket 105 (FIGURE 3) mounted on thedrive shaft 107 of the motor is coupled through a chain 108 to a drivensprocket 110 secured onto a vertically extending propelling shaft 112rotatably mounted in end bearings 114 and 115 fastened to the bridgingchannel 95 and to the base plate 97 at opposed ends of the probe drivingunit 30. The propelling shaft 112 is provided with external threads 117extending along its length. A cross-head or probe clamp 119 providedwith a cooperating threaded sleeve 121 is fastened onto the threadedshaft 112 so that the sleeve engages and travels along the shaft as theshaft rotates. Extending longitudinally from opposite ends of thecross-head are stub shafts 122 and 123 which extend into the opposedfacing channels 92 and 93 and carry rollers or guides 124 and 125journaled on the shafts. The rollers ride within the guideways definedby the channels 92 and 93. The probe 18 is rigidly and firmly fastenedadjacent its upper end into a clamp integral with the cross-head 119whereby the probe 18 is moved upward or downward with the screw-drivencross-head as the motor-driven threaded shaft 112 is rotated. As shownin FIGURE 1, the free end of the probe 18 extends through the packinggland 20 in the top wall 21 of the vacuum chamber 11. In an alternativearrangement probes may be inserted into the hogsheads or bales prior toplacing the hogsheads in the evacuation or conditioning chamher. Theexposed ends of the probes are then coupled to hoses or pipes for vacuumand for steam treatment of the material contained in the hogsheads orbales.

For the purpose of illustrative disclosure, and not by way oflimitation, a preferred processing and conditioning cycle is depictedschematically in FIGURE 5. The entire system including the probe lines,the probes, and the sealed chamber containing one or more hogsheads oftobacco to be treated, is subjected to an initial evacuation by means ofthe second stage steam ejector 62 (FIGURE 1) to remove most of the gasfrom the chamber. The first stage ejector is then actuated to continuethe evacuation through the chamber and through the probes to achieve afinal presure of about 0.3 inch of mercury (C) absolute. In the cycleillustrated, this initial high evacuation requires about 7 minutes.Moisturizing steam is then introduced concurrently (C-D-E) into thechamber 11, as indicated schematically by the arrows through line 56 andinto the interior of the tobacco through lines 47, 45, 44 and the probes18, with valve 33 closed.

The pressure in the system is increased (D) to a value of about 10inches of mercury corresponding to a temperature of about 162 F. (E).Utilization of steam which is saturated is ensured by introducing Waterinto the steam line through valves 61 and 63 downstream of the controlvalves 52 and 57 and upstream of the probes and the conditioningchamber. Superheating is thus obviated and excess moisture is madeavailable for plating on the tobacco. Introduction ofsteam-desuperheating water into the probe line may be delayed a shortperiod of time to avoid an excess of water at the start of the steaming,thus preventing wetting of the tobacco. Steam control valves 49 and 57are closed to terminate steam introduction and the system is reevacuated(F), after an optional holding period, preferably through both thechamber and the probes, as indicated schematically by the arrows (FIGURE5), though evacuation through the chamber only, indicated schematicallyby the arrow in FIG- URE 5, may be satisfactory in some instances. Inanother preferred reevacuation cycle, steam is introduced into the probewhile the system is evacuated through the chamber, at leastfor a portionof the reevacuation period, as indicated schematically by the arrows inFIG- URE- 5. During each reversal, from evacuating to steaming, andvice-versa, there are inflections in the pressure and temperature versustime curve. These discontinuities or shifts and flow reversals causepulsing within and fluffing of the tobacco contained in the hogsheadsenhancing moisture penetration and greatly minimizing any likelihood ofcold spots. During the gas or steam flow reversals (D) and (F) or anysubsequent flow reversal during evacuation and steaming, the equilibriumpressure Within the system will decrease and increase with correspondingdecreases and increases in temperature.

In the second evacuation (EFG) the pressure is reduced to about 2 inchesof mercury, corresponding to a system temperature of about F. asindicated in FIGURE 5 (G). Steam is again introduced into the chamberand through the probes (H) causing additional pulsing of the tobacco toloosen the pack and fluff the tobacco. As pointed out above, therelative direction of steam flow into the system is indicated by arrowsin FIGURE 5. In FIGURE 5, arrows directed inwardly or away from thelateral boundaries of a given cycle stage represent flow of steam intothe system. Arrows directed outwardly or toward the lateral boundariesof a cycle stage (6 represent evacuation from the system. v

If preferred, the 162 F. temperature (E) maybe held for about one minutebefore the reevacuation steps (F) to ensure insect destruction. Duringthe second steaming (H), preferably through both the chamber and theprobe the system pressure is increased to about 5 inches of mercury andthe temperature is raised to about F. (I). At this stage, the vacuum isbroken (I) returning the chamber to atmospheric pressure and completingthe cycle. The over-all cycle requires about 20 minutes. In the interestof shortening the conditioning time one skilled in the art may readilymodify the steps of cycle to complete the treatment within about 16-18minutes, or even less. The grade, type, and the original condition orstate of the tobacco will be an important consideration when schedulingany preferred c cle.

The novel methods of tobacco conditioning which are the essence of thepresent invention, will be described with reference to the apparatusillustrated in the drawings. Tobacco contained in hogsheads 13 orbarrels is loaded onto wheeled trucks 14 positioned on the trackway 16and the trucks are moved into the conditioning chamber to predeterminedpositions such that the vertical axes of the hogsheads are substantiallyin alignment with the vertical paths of travel of the probes 18. Theprobes 18 are forced into the tobacco to bring the points 37 to aposition adjacent the bottom of the hogsheads 13. With the door 12 tothe chamber sealed, the conditioning or treatment cycle may beinitiated.

' Basically, the method of the invention contemplates a simpleyet'highly effective processing cycle including the following steps. Thesystem is evacuated through the chamber and through the probes, thisinitial evacuation being to a relatively high degree ensuring that thepressure in the system is below the equilibrium vapor pressure" of waterin the chamber so that the moisture boils off and non-condensible gasesare removed. The initial rate of evacuation is not critical butimportant economies are achieved through shortened time cycles. In atypical cycle, the initial evacuation requires about 6 to about minutes.Chamber volumes and equipment considerations will control, but rapidevacuation is preferred. With substantially all of the air and othergases removed from the chamber, and the system pressure in the range offrom about 0.15 inch to about 1.0 inch of mercury, and preferably atabout-0.3 inch, the initial moisturization is carried out. Steam isintroduced directly into the chamber and simultaneously into the probesso that moisture penetrates the tobacco from the outer surface inwardlyand from the center or core radially outwardly. Water is added to thesteam as a spray to ensure saturation and to preclude superheating.During this steaming step the pressure in the system is graduallyincreased and the temperature within the chamber and Within the tobaccorises. In a preferred cycling process, the pressure is increased to fromabout 6 to about inches of mercury and the temperature rises to acorresponding value of from about 140 F. to about 180 F. In a modifiedcycle, the initial evacuation and steaming may be through thechamber'only.

The highest temperature reached. is not critical, but it is desirable inthe processing of the tobacco to reach a temperature at which insectdestruction is assured. Tests carried out indicate that an expectedtemperaturetime relationship exists. For example, kill or destruction ofegg, larva, pupa, and adult moths, beetles, and other insects isachieved in about 1 minute at 170 F., and in about 3 minutes at 150 F.-It may be expected that longer times at somewhat lower temperatures maybe effective. At still more elevated temperatures shorter times willsuffice. Again, in the interest of reducing the processing. time, thegenerally higher temperatures are preferred. However, other obviousconsiderations, including possible deleterious effects upon the tobacco,dictate against temperatures which are too high.

The flow of steam through the tobacco is then reversed by reevacuatingthe system through the chamber and through the probe (-E-F-G), orthrough the chamber alone, if preferred. During the reversal or theswitching of the direction of steam flow through the tobacco, thepressure in the ambient system decreases (F) and the temperature drops(G). In a somewhat modified reevacuation cycle, steam is introducedthrough the probes 6 while evacuating through the chamber, enhancing theflufiing of the tobacco.

The reversal of flow, which is preferably relatively abrupt, causesphysical phenomena such as pulsings which have several important effectsupon the packed tobacco and upon the completeness of air removal fromand steam penetration into and upon the uniformity of steam penetrationinto the product treated. That is, the physical agitation or disturbanceis conducive to and promotes the formation of new and an increasednumber of flow paths through the tobacco and tends to minimizechanneling. The number of cold spots" is greatly reduced and, in mostcases, cold spots are practically eliminated. A more uniform ultimateproduct is obtained and processing losses attributable to powdering areminimized. Since the effectiveness of the reverse flow technique of theinvention is enhanced upon repetition of the steps described, it ispreferred to include in the process cycle at least two flow reversals orflow reversal stages.

In the re-evacuation step (F) it is not necessary to achieve the highdegree of evacuation of the initial process step. Re-evacuation ispreferably from both the chamber and the probes until a pressure ofabout 2 inches of mercury and a corresponding temperature of about F.are reached. Appreciable fluifing of the tobacco is achieved during there-evacuation step.

In the final steps of the cycle, steam is introduced into the systemthrough the chamber and throughthe probes (GH-I) to force steam inwardinto the tobacco and radially outwardly, concurrently. The finaltemperature to be reached may be any desired value but is preferably inthe range of from about F. to about 145 F. corresponding to a pressurein the range of from about 4 inches to about 7 inches of mercury. Asuitable ultimate steam pressure is about 5 inches of mercury,

corresponding to a temperature of about 135 F. (I),

If preferred, the system may be subjected to a holding period of fromabout /2 to about 3 minutes at this temperature and pressure to ensurethat equilibrium is achieved throughout the contents of the hogshead.The more slowly the final temperature is approached, the shorter is therequired holding period. It may, if preferred, be eliminated completely.The final step is to break the vacuum, opening the system to theatmosphere to return the system to ambient temperature and pressure. Apreferred procedure is to introduce air through the probes in order toenhance the fluffing of the tobacco.

The novel arrangement of the structural elements of the apparatus hasbeen described with reference to the new methods and processingprocedures of the invention. It may be desired, however, to use theequipment in carrying out more conventional processing cycles notcalling for use of probes. Under such circumstances a preferredprocedure is to withdraw the probe 18 upwardly through the ceilingopening so that substantially the entire probe shaft is outside of thevacuum chamber 11. As illustrated in FIGURE 6 a stub pipe section 132coaxial with the probe shaft is welded or otherwise connected at theceiling 21 and extends'downwardly into the chamber. The pipe section 132is threaded at its lower end 134 and a cooperating threaded cap 136 isprovided to seal the lower or depending end of the pipe section. Thus,with the shaft of the probe rctracted to clear the lower end of thedownwardly extending pipe and the sealing cap 136 afiixed in position,the chamber may be used in carrying out procedures not involving use ofthe probes.

Throughout the description and in the specific examples, the inventionhas for the most part been explained with reference to the treatment orconditioning of tobacco. However, the utility of the methods and of theappartus disclosed and claimed is not to be construed as limited orrestricted in any way to any particular product or group of products.The inventive concept embraces all materials which may advantageously beprocessed or treated in accordance with: the processes and techniques ofthe invention. The bulk product which is treated in the chamber of theconditioning apparatus may be in any gross physical shape or packagedform including but not limited to bales and hogsheads. Throughout thespecification: and in the claims the terms bales and/or hog'shead's areused not in: any limiting sense but as equivalents and one term isintended to include the other;

While disclosures of preferred" embodiments of the apparatus and ofpreferred methods of the invention have been provided, it will beapparent that numerous modifications andvariations thereof may be madewithout departing from underlying principles of the invention. It is,therefore, desired by the following claims to include within the scopeof the invention all such variations and modifications by whichsubstantially the results of this invention may be obtained through theuse of substantially the same or equivalent means.

What is claimed is:

1'. The method of humidifying and increasing the volume of a tobaccopack contained in a bale, hogshead or box to provide a uniformlymoisturized tobacco prodnet and comprising the steps of:

placing said pack in a vacuum chamber provided with means forestablishing subatmospheric pressures and with means for introducingsteam vapor in said chamber; inserting a probe having a longitudinalbore and radial openings in communication with said bore into saidtobacco pack axially, in the center thereof, for substantially the fullvertical height of said pack;

evacuating said chamber through a bounding wall thereof andsimultaneously evacuating air and other gases through said probe toestablish a pressure of about 0.3 inch of mercury absolute in saidchamber and Within said pack;

introducing steam into said chamber through a wall thereof to penetratesaid tobacco pack from outer surfaces thereof inwardly whilesimultaneously introducing steam through said probe to travel throughsaid pack radially outwardly to fluff the tobacco in the pack and toincrease the volume thereof, to bring the pressure in said chamber andsaid pack to about 10 inches of mercury absolute and the temperature toa corresponding value of about 162 F.;

reevacuating said chamber while simultaneously introducing steam intosaid tobacco pack through said probe to reverse steam flow through saidpack and to reduce the pressure within said chamber to about 5 inches ofmercury absolute and the temperature to a corresponding 135 F.; and

restoring the pressure in said chamber and in said pack to atmosphericpressure and the temperature to ambient temperature to provide auniformly moisturized tobacco product.

2. The method of claim 1 wherein restoration of the pressure in saidchamber and in said pack to atmospheric pressure comprises the step ofintroducing air into said pack and into said chamber through said probein said pack.

3. The method of conditioning a mass of tobacco contained in a bale orhogshead in a vacuum chamber to provide a uniformly moisturized andhumidified product of increased over-all bulk and comprising the stepsof:

driving a probe having a longitudinal bore and radial Openings incommunication with said bore axially into said tobacco mass insubstantially the center thereof for substantially the full length ofsaid mass; evacuating said chamber through a bounding wall thereof to anabsolute pressure in the range of from about 0.15 inch to about 1.0 inchof mercury, while simultaneously evacuating through said probe to 8remove substantially all air and other gases from said mass of tobacco;introducing steam into said chamber through abounding wall thereof andsimultaneously through said probe to bring the absolute pressure withinsaid chamber and within said tobacco tofrom about 6 to about 15 inchesof mercury and to bring: the temperature within said chamber and saidtobacco in the range of about 140 F. to about 180 F'.;.

reevacuating through said chamber while simultaneously introducing steaminto said mass of tobacco through said probe to fluff said tobacco andto bring the pressure within said chamber and said tobacco to about 2inches of mercury and the temperature to about F.;

reintroducing steam into said tobacco through said chamber and throughsaid probe to increase steam pressure within said tobacco to a value ofbetween about 4 inches to 7 inches of mercury and the temperaturetherein to from about F. to about F., and to reverse steam flow throughsaid tobacco to provide a substantially uniformly humidified tobaccoproduct; and

bringing said vacuum chamber and said mass of tobacco to atmosphericpressure and ambient temperature.

4. The method of conditioning a mass of tobacco con.- tained in a baleor hogshead in a vacuum chamber to provide a uniformly humidifiedproduct and comprising the steps of:

inserting a perforated probe axially into said tobacco mass insubstantially the center thereof for substantially the full depth ofsaid mass; evacuating said chamber through a bounding wall thereof andconcurrently evacuating through said probe to remove substantially allof the air from said chamber and substantially all of the air and othervolatile gases from said mass of tobacco;

introducing steam directly into said chamber to enter said mass oftobacco from outer surfaces thereof inwardly While simultaneouslyintroducing steam through said probe to permeate said tobacco radiallyoutwardly from said probe;

reevacuating through a bounding wall of said chamber to reverse the flowof steam through said tobacco; and

resteaming said tobacco mass through said chamber and through said probeto provide uniformly humidified tobacco.

5. The method of conditioning a mass of tobacco contained in a box, abale, or hogshead in a vacuum chamber to provide a uniformly humidifiedproduct and comprising the steps of:

inserting a perforated probe axially into said tobacco mass insubstantially the center thereof for substantially the full depth ofsaid mass; evacuating said chamber through a bounding wall thereof andconcurrently evacuating through said probe to remove substantially allof the air from said chamber and substantially all of the air and othervolatile gases from said mass of tobacco;

introducing steam directly into said chamber to enter said mass oftobacco from outer surfaces thereof inwardly while simultaneouslyintroducing steam through said probe to permeate said tobacco radiallyoutwardly from said probe;

reevacu-ating through a bounding wall of said chamber and through saidprobe to reverse the flow of steam through said tobacco; and

resteaming said tobacco mass through said chamber and through said probeto provide uniformly humidified tobacco.

6. The method of conditioning a mass of tobacco contained in a bale orhogshead in a vacuum chamber to provide a uniformly humidified productand comprising the steps of:

pack. I

driving a probe having a longitudinal bore and radial openings incommunication with said bore axially into said tobacco mass insubstantially the center thereof for substantially the full length ofsaid mass;

evacuating said chamber through a bounding wall thereof to an absolutepressure in the range of from about 0.15 inch to about 1.0 inch ofmercury, while simultaneously evacuating through said probe to removesubstantially all air and other gases from said mass of tobacco;

introducing steam into said chamber through a bounding wall thereof andsimultaneously through said probe to bring the absolute pressure withinsaid chamber and within said tobacco to from about 6 to about 15 inchesof mercury and to bring the temperature within said chamber and saidtobacco in the range of about 140 F. to about 180 F.;

reevacuating through said chamber and said probe to reverse the flow ofsteam through said mass of tobacco, to fluff said tobacco, and to bringthe pressure within said chamber and said tobacco to about 2 inches ofmercury and the temperature to about 100 F.;

reintroducing steam into said tobacco through said chamber and throughsaid probe to increase steam pressure within said tobacco to a value ofbetween about 4 to about 7 inches of mercury and the temperature thereinto from about 120 F. to about 145 F., and to reverse steam fiow throughsaid tobacco to provide a substantially uniformly humidified tobaccoproduct; and

bringing said vacuum chamber to atmospheric pressure and ambienttemperature.

7. The method of humidifying a tobacco pack contained in a bale orhogshead to provide a uniformly moisturized tobacco product andcomprising the steps of:

placing said pack in a vacuum chamber provided with means forestablishing subatmospheric pressures and with means for introducingsteam vapor in said chamber;

inserting a probe having a longitudinal bore and radial openings incommunication with said bore into said tobacco pack axially, in thecenter thereof, for substantially the full vertical height of said pack;

evacuating said chamber through a bounding wall thereof andsimultaneously evacuating air and other gases through said probe toestablish a pressure of about 0.3 inch of mercury absolute in saidchamber and within said pack;

introducing steam into said chamber through a wall thereof to penetratesaid tobacco pack from outer surfaces thereof inwardly whilesimultaneously introducing steam through said probe to travel throughsaid pack radially outwardly and to bring the pressure in said chamberand said pack to about 10 inches of mercury absolute and the temperatureto a corresponding value of about 162 F.;

reevacuating said chamber and said probe to reverse steam flow throughsaid pack and to reduce the pressure Within said chamber and said packto about 5 inches of mercury absolute and the temperature to acorresponding 135 F.; and restoring the pressure in said chamber toatmospheric pressure and the temperature to ambient temperature toprovide a uniformly moisturized tobacco product.

8. The method of claim 7 wherein restoration of the pressure in saidchamber and in said pack to atmospheric pressure comprises the step ofintroducing air into said pack and into said chamber through said probein said 9. The method of conditioning a mass of tobacco condriving aprobe having a longitudinal bore and radial openings in communicationwith said bore axially into said tobacco mass in substantially thecenter thereof for substantially the full length of said mass;

evacuating said chamber through a bounding wa ll thereof to an absolutepressure in the range of from about 0.15 inch to about 1.0 inch tomercury to remove substantially all air and other gases from said massof tobacco;

introducing steam into said chamber through a bounding wall thereof tobring the absolute pressure within said chamber and within said tobaccoto from about 6 inches to about 15 inches of mercury and to bring thetemperature Within said chamber and said tobacco in the range of fromabout 140 F. to about 180 F.;

re-ev-acuating through said chamber to bring the pressure within saidchamber and said tobacco to about 2 inches of mercury and thetemperature to about F.;

re-introducing steam into said tobacco through said probe to increasesteam pressure Within said tobacco to a value of between about 4 inchesto about 7 inches of mercury and the temperature therein to from aboutF. to about 145 F., and to reverse steam flow through said tobacco toprovide a substantially uniformly humidified tobacco product; and

bringing said vacuum chamber and said mass of tobacco to atmosphericpressure.

10. The method of conditioning a mass of tobacco contained in a bale orhogshead in a vacuum chamber to provide a uniformly humidified productand comprising the steps of:

driving a probe having a longitudinal bore and radial openings incommunication with said bore axially into said tobacco mass insubstantially the center thereof for substantially the full length ofsaid mass;

evacuating said chamber through a bounding Wall thereof to an absolutepressure in the range of from about 0.15 inch to about 1.0 inch ofmercury to remove substantially all air .and other gases from said massof tobacco;

introducing steam into said chamber through a bounding wall thereof tobring the absolute pressure Within said chamber and Within said tobaccoto from about 6 inches to about 15 inches of mercury and to bring thetemperature within said chamber and said tobacco in the range of fromabout F. to about 180 F.;

re-evacuating said chamber through a bounding wall thereof andsimultaneously re-evacuating air and other gases through said probe tobring the pressure within said chamber and said tobacco to about 2inches of mercury and the temperature to about 100 F.;

re-introducing steam into said tobacco through said probe to increasesteam pressure within said tobacco to a value of between about 4 inchesto about 7 inches of mercury and the temperature therein to from about120 F. to about F., and to reverse steam flow through said tobacco toprovide a substantially uniformly humidified tobacco product; and

bringing said vacuum chamber and said mass of tobacco to atmosphericpressure.

References Cited UNITED STATES PATENTS 2,900,986 8/ 1959 Pietruska131-134 3,124,142 3/1964 Philbrick et al. 131-133 6,131,700 5/1964'RadWan 131-140 3,262,458 7/1966 Lindstrom 131133 3,272,207 9/1966 Doyle131-133 75 ALDRICH F. M-EDBERY, Primary Examiner.

4. THE METHOD OF CONDITIONING A MASS OF TOBACCO CONTAINED IN A BALE ORHOGSHEAD IN A VACUUM CHAMBER TO PROVIDE A UNIFORMLY HUMIDIFIED PRODUCTAND COMPRISING THE STEPS OF: INSERTING A PERFORATED PROBE AXIALLY INTOSAID TOBACCO MASS IN SUBSTANTIALLY THE CENTER THEREOF FOR SUBSTANTIALLYTHE FULL DEPTH OF SAID MASS; EVACUATING SAID CHAMBER THROUGH A BOUNDINGWALL THEREOF AND CONCURRENTLY EVACUATING THROUGH SAID PROBE TO REMOVESUBSTANTIALLY ALL OF THE AIR FROM SAID CHAMBER AND SUBSTANTIALLY ALL OFTHE AIR AND OTHER VOLATILE GASES FROM SAID MASS OF TOBACCO; INTRODUCINGSTEAM DIRECTLY INTO SAID CHAMBER TO ENTER SAID MASS OF TOBACCO FROMOUTER SURFACES THEREOF INWARDLY WHILE SIMULTANEOUSLY INTRODUCING STEAMTHROUGH SAID PROBE TO PERMEATE SAID TOBACCO RADIALLY OUTWARDLY FROM SAIDPROBE; REEVACUATING THROUGH A BOUNDING WALL OF SAID CHAMBER TOR REVERSETHE FLOW OF STEAM THROUGH SAID TOBACCO; AND RESTEAMING SAID TOBACCO MASSTHROUGH SAID CHAMBER AND THROUGH SAID PROBE TO PROVIDE UNIFORMLYHUMIDIFIED TOBACCO.